Build everything as C++ (#1176)

include/link/symbol.hpp

@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: MIT */
+
+// Declarations manipulating symbols
+#ifndef RGBDS_LINK_SYMBOL_H
+#define RGBDS_LINK_SYMBOL_H
+
+// GUIDELINE: external code MUST NOT BE AWARE of the data structure used!
+
+#include <stdint.h>
+
+#include "linkdefs.hpp"
+
+struct FileStackNode;
+
+struct Symbol {
+	// Info contained in the object files
+	char *name;
+	enum ExportLevel type;
+	char const *objFileName;
+	struct FileStackNode const *src;
+	int32_t lineNo;
+	int32_t sectionID;
+	union {
+		// Both types must be identical
+		int32_t offset;
+		int32_t value;
+	};
+	// Extra info computed during linking
+	struct Section *section;
+};
+
+/*
+ * Execute a callback for each symbol currently registered.
+ * This is done to avoid exposing the data structure in which symbol are stored.
+ * @param callback The function to call for each symbol;
+ *                 the first argument will be a pointer to the symbol,
+ *                 the second argument will be the pointer `arg`.
+ * @param arg A pointer which will be passed to all calls to `callback`.
+ */
+void sym_ForEach(void (*callback)(struct Symbol *, void *), void *arg);
+
+void sym_AddSymbol(struct Symbol *symbol);
+
+/*
+ * Finds a symbol in all the defined symbols.
+ * @param name The name of the symbol to look for
+ * @return A pointer to the symbol, or NULL if not found.
+ */
+struct Symbol *sym_GetSymbol(char const *name);
+
+/*
+ * `free`s all symbol memory that was allocated.
+ */
+void sym_CleanupSymbols(void);
+
+#endif // RGBDS_LINK_SYMBOL_H